On September 7-8, 2007 Gerry Trione, Rex Ross and Julian Lamborn visited the
University
of Texas
McDonald Observatory near Fort Davis, Texas.

The purpose of the visit was to tour the facilities and to learn about HETDEX, the exciting major new research project
to investigate "dark energy".

The drive from Midland Airport to McDonald Observatory in the Davis
Mountains
went through some beautiful country. We arrive at the site.David Lambert, Director of the McDonald Observatory,
graciously accommodated us in his lodge at the site.The Lambert Lodge is quite nice.

The views from the deck of Lambert Lodge were spectacular.
Director David Lambert (2nd from right) welcomes us to McDonald
and discusses
the agenda for our stay.(Left to right) Julian Lamborn, Joel Barna ((U.T. Development
Manager for McDonald Observatory), Don Wallace (Superintendent of McDonald Observatory)
and
Rex
Ross
identify
either a new super-nova or a Southwest Airline Jet.

Hobby-Eberly Telescope

Primary Mirror: 91 hexagonal segments

Mirror Weight: 26,000 pounds

Mirror Diameter: 36 feet

Telescope Weight: 160,000 pounds (80 tons)

Dedicated: October 8, 1997

Gary Hill (on left) Senior Research Scientist and Chief Astronomer joined us for
our first stop: The Hobby-Eberly Telescope.
The 9.2. meter mirror of the HET can be seen in the center of each photo.A staff member climbs the structure to make some adjustments.
HET Site Manager Bob Calder (on right) shows a replacement mirror
for one of the 91 hexagonal segments of the
telescope.Each hexagonal segment is quite delicate, with an aluminum reflective coating 900 angstroms thick.
Our group examines the telescope's 80 ton structure.
Rex (closely supervised by Bob Calder) is allowed to "drive" the telescope to move it into the proper position.The side louvers of the telescope building can be opened as part of
the temperature controls.
In the control room for the Hobby-Eberly telescope,
Eusebio Terrazas (HET Telescope Operator) monitors several
computer
screens that
show the telescope's position, operation and alignment.
HET Site Manger Bob Calder explains the operation of the HET.

Below right shows additional screens
that monitor the
digital image being recorded by the telescope.Gerry ponders improvements to the telescope that he would like to suggest .Our group discusses the operations and research activities associated with HET.
(left to right) David Lambert, Gerry Trione, Rex Ross, Julian Lamborn and Gary Hill
pose for
a last photograph with the HET.
Back at Lambert House for a pre-dinner cocktail and further discussion.We adjourn to the "Astronomer's Lodge" for dinner.
Rex comments on Director Lambert's research project involving stars with no
hydrogen (trust me - that's a peculiar type of star) .

After dinner, Gary Hill provides an in-depth review of the HETDEX project that he is leading.

HETDEX: The Hobby Eberly Telescope Dark Energy Experiment

The Issue Simplified (with apologies to the cosmological community)

Several decades ago it was determined that the universe is expanding.

More recently, it has been determined that the rate of that expansion is accelerating.

No one yet understands the mechanism that is causing that acceleration.

One theory is that some "dark energy" which we cannot yet see nor measure, may be that mechanism.

The HETDEX will examine two million galaxies to map how fast galaxies are moving away from us as a
basis to attempt to understand what this "dark energy" may be.

As Gary Hill clearly noted in his presentation, "Dark Energy" may not be
dark and may not be energy. But therein lies the puzzle that Gary's project
will attempt to unravel.

Julian and Rex ponder Gary's presentation.

Following the review of HETDEX, a beautiful sunset greets us as we make
our way to visit the Harlan Smith Telescope.

Harlan J. Smith Telescope

Mirror Weight: 7,800 pounds

Mirror Diameter: 107 inches

Telescope Weight: 320,000 pounds (160 tons)

Length: 32 feet

Dedicated: November 26, 1968

The 107 inch Smith telescope towers over our group.
Gary Hill and David Lambert explain the newly designed spectrograph
(the black unit at the base of the telescope)
that has been designed and
built
by his
team
as the key element for the HETDEX project.

The specially designed spectrograph is named Visible Integral-Field Replicable Unit Spectrograph ("VIRUS").

Once operational, HETDEX will employ a set of 145 such VIRUS units linked
together, permitting the
HET to examine 10,000 galaxies each night.

Another group photograph in the shadow of the Smith Telescope.In the control room for the Smith Telescope, Gerry discusses the shape of the solar system with
Gary Hill (below left) and explains some finer points of photons to Phillip
MacQueen (McDonald Chief Scientist) (below
right).

Part of the instrumentation to direct light from the Smith telescope to
the Spectroscopy
laboratory in a lower level of the building is shown here.Director Lambert explains the operation of the spectroscopy laboratory where the nature of stars, galaxies and
other objects is deduced by examining the spectrum of the light from those objects.
The pressure chamber used to re-coat the reflective surface of the
Smith telescope lens is discussed.

Otto Struve Telescope

Mirror Weight: 4,200 pounds

Mirror Diameter: 82 inches

Telescope Weight: 90,000 pounds (45 tons)

Length: 27 feet

Dedicated: May 5, 1939

David Lambert explains the layout of the Otto Struve Telescope.
Note that this telescope has an eye viewing lens at its base, unlike more
modern instruments which all acquire digital images.Early telescopes often included a small "spotting scope" as shown on the left
photo and angular degree scales as shown on the right photo to help
locate objects. Current alignment of telescopes is fully computer controlled.

Nevertheless, when the Struve Telescope was dedicated in 1939 it was the second largest telescope in the world and one of the most
technologically advanced.Following a hearty breakfast the next morning,
Julian, Rex and Gerry pose for a farewell photograph.Our fascinating exposure to the McDonald
Observatory staff, facilities, operations and
research programs comes to an end.